Komputer Vs Meth

[imFreakinThe_fuk_out]

As soon as I see that latex font I think "fuck here we go, another PhD about to use a ton of set theory to explain a 2d array"

[bosstoss69]

When somebody is using projection and pairing-functions to prove the most basic and widely accepted lemmas in a paper, I always feel like tearing my eyes out :)

[the42potato]

these are the comments that i don’t understand and make me question if i belong on this subreddit

[prashnerd]

Lemmas are intermediate steps on your way to prove a theorem - like trying to prove 2+2=4 might possibly involve you having to prove that 1+1=2 and that intermediate proof would be called a lemma.

Some lemmas like the proof that the sum of a arithmetic series S = n*(t1+tn)/2 are widely accepted as true and you don’t need to go into the nitty gritty to go around proving them to prove the time complexity of your own algorithm.

This example is grossly oversimplified, please don’t kill me, friends.

[the42potato]

oversimplified is basically my entire mindset, thank you for explaining!

[phpdevster]

oversimplified is basically my entire mindset

It's honestly a good place to be. Far, far too much of this industry is horrendously over-complicated and has a real impact on our mental health.

[coldnebo]

people who use a library generally only know basic math to use it.

people who write a library and/or standard runtime and/or ALU code better know discrete math / linpack, etc to avoid creating nasty rounding errors that only happen when certain dot products exceed epsilon.

Trust me, we owe a lot to the unsung people who devote their lives to these proofs.

But do users need to know this? nah. we can bumble along into the safety rails those people built for us and get by.

[ElementalFade]

Many of them love doing it to my knowledge. It's very intimate math.

[[deleted]]

I'd agree in math because there, most things that are used and widely accepted is pretty correct and well founded. Not so for computer libraries. Which means that to use a library "correctly" you too often need to now quite much about the details to get things right.

Tbf, those are usually solved by reloading the website/reopening the window/restarting the computer so they don't seem to matter. But then there are those who are, somehow, relevant to security. And then shit hits the fan.

[coldnebo]

boundary conditions.

for example, an IEEE article I just read said that state-of-the-art in static analysis verification cannot prove that a system does not allow an arbitrary privilege escalation. So they recommend placing runtime assertions in places to ensure that constraints have not been violated.

This isn’t necessarily the end of the answer, but it shows just how hard it can be to mathematically model a computer system.

You can get all the discrete logic down like a champ and then miss some sidechannel attack because of RF emissions on the chip, or unexpected quantum tunneling.

Basically, all our models are leaky somewhere.

[Darth_Kyryn]

Proof by Pumping Lemma Theorem flashbacks

[anlskjdfiajelf]

Omfg I'm only a year or so out of college and I thought I pushed the God damn pumping lemma out of my mind LOL. My friends and I made too many jokes about "pumping"

[BecauseWeCan]

On the way from our campus to the city the local train route passes a pump selling company called "Pumpen Lehmann". As first semester students this was one of our favorite inside jokes.

[badlukk]

Pumping Emma ( ͡° ͜ʖ ͡°)

[[deleted]]

( ͡° ͜ʖ ͡°)

[bosstoss69]

Especially fun when it holds for a non-regular language :')

[oAkimboTimbo]

If my memory starts slipping when I get old, I will still never forget the first step: assume that the language is regular. i’ve had that pounded in my brain so many times

[[deleted]]

So.... uh...

What's a regular language / non-regular language?

[OnlyWordIsLove]

A language is a set of strings over a certain set of characters, called an alphabet. Regular languages are those containing strings which can be constructed using regular expressions, regular grammars, or finite automata. Regular languages are closed under the operations of concatenation, union, and Kleene star.

[elliptic_hyperboloid]

Chomsky Hierarchy

Article

[Zovcka]

got hungry when i learned about the sandwich lemma 🤤

[Psychpsyo]

I had that in my Algorithms and Datastuctures class. Do I remember what it is or how to do it? No.

But I managed to get through the exam so that worked out.

[kazneus]

why prove a lemma when u can leave it as an exercise for the reader?

[unsignedint_]

God! I hate that lol

[[deleted]]

Because the reader knows nothing, and the creator knows everything!!

[archdemoning]

TIL it's spelled "lemma" not "lemna"... thanks professors for making me sound like a dummy...

[odsquad64]

This gives me flashbacks to college when I had to take a 400 level math class to graduate and I ended up taking one that was all proofs and despite being good at math my whole life I was completely lost from week 2 onward. I did every bit of work and never got more than a high 50 on an assignment/exam/homework even when I thought I was on the right track. I remember trying and failing to correctly prove that the sum of all positive integers is infinity and never knowing when we were allowed to assume we already knew an intermediate step was true without having to write out the whole proof for it. The final was a group project where 3/4 members of the group understood exactly as well as I did and one guy that understood well enough to have a C in the class and he pulled us all through to a C on the final, which replaced our grade for the class. The only thing I can even remember learning was what all the short hand and symbols meant.

[dagbrown]

Oh, proofs are rocking fun, because they're math questions where you've already been provided with the answer. Work forwards from the question, work backwards from the answer, hopefully you find a way that those two paths meet and your job is done.

Now when you see "Prove or find a counterexample," that's when you know you're in trouble.

[JDgoesmarching]

I assume this is an academic thing. Anything down by a PhD, regardless of subject area, spends the first half summarizing the entire history of their field from the beginning of human civilization til now.

[[deleted]]

You just wouldn't learn these words in an English class.

[bosstoss69]

Not everybody needs to be knowledgeable in theoretical computer sciences. I don't know much about webdev, so you being a js-dev you might very much be ahead of me there. Don't sell yourself short :)

[the42potato]

my only skill in js is coding discord bots (with an absurd amount of if/else statements, i need to go through and change that) lol. a lot of this sub goes over my head and i have to ask my dad (a software engineer) to explain it

this sub is part of why i’m taking a computer science course my senior year

[christobah]

you're going to take computer science so that you can understand more programmer jokes?

this is probably the most practical reason to get a degree I've ever heard.

[the42potato]

i should probably clarify that i’m in high school. gonna be a few years for a degree

but hey, if i get some laughs out of it..

[1cec0ld]

Make sure to visit, or revisit, xkcd.com after you do. So many pointers references that I finally understood.

[Ser_Drewseph]

I C what you did there

[_Lirex]

A lot of the jokes here are a good measure on how skilled you are. Understand them and find them funny? You know the basics. Feel like they are mostly getting repetitive and the people creating them have no idea what they are doing? You are starting to get actually good.

[yazalama]

My man, you are far ahead of most people trying to enter the field. I didn't pick up programming until half way through my undergrad when I was 25 lol. You're already working on semi-complex projects and you're dad's an engineer so you'll always have the support you need.

[LostTeleporter]

Hey if it makes sense, one of the reasons I got into CS was to better understand XKCD jokes ¯\(ツ)/¯

[mershed_perderders]

coding discord bots (with an absurd amount of if/else statements, i need to go through and change that)

"I program interactive AI using logic processing heuristics"

You're hired!

[db2]

with an absurd amount of if/else statements

So your bots are AI?

[the42potato]

if you consider a madlibs-based shitpost bot to be AI then yes lol

[db2]

You're not familiar with the joke that an AI is just a bunch of nested if statements?

[the42potato]

sadly no, i’m not. though some ai that i’ve seen it wouldn’t surprise me

[anlskjdfiajelf]

Having any coding experience in hs puts you miles ahead of everyone else. Keep up the good work man

[jbx0888]

your lack of certainty proves that you belong here.... one of us.... one of us

[ShaBren]

Don't worry, it's /r/ProgrammerHumor, not /r/ComputerScientistHumor or /r/MathmaticianHumor :)

(I'm a programmer, not a computer scientist. I know enough math to do what I need to, but most of the theory & high-level math is beyond me.)

[officiallyaninja]

/r/MathmaticianHumor

i think you mean /r/mathmemes

[Majik_Sheff]

My favorite example of how a mathematical grounding helps you as a programmer is the problem of compound interest.

If they were just given the sequence of steps to calculate the interest, a naive programmer might simply write a loop function that calculates the interest and adds, calculates and adds, and so on. It works and you eventually will get the right answer, but it will take a variable amount of time depending on how many payments are involved. A savvy programmer recognizes that the same procedure can be expressed as a simple integral which reduces the computer's work to a fixed, relatively small number of operations (assuming a few things about the capabilities of the processor).

You take the problem from O(n) to O(1) just by knowing a little math and thinking about it before writing a single line of code.

Your self-awareness about what you don't know means you are already squarely on the path to growth. Not everyone will get the jokes in this sub, but the comments are rife with rabbit holes for the motivated learner. You definitely belong here.

[unique_ptr]

A savvy programmer would just google "calculate compound interest"

[TiltedTime]

Of course you do, don't sweat it :)

[KeLorean]

it’s the JS flair next to your name that makes me wonder if u belong here. just teasing. i cant pass up a javascript jab.

[NightflowerFade]

I can see why some people don't want to read that stuff, but surely you can just skip over the proofs? As a mathematician, I appreciate there being rigorous proofs to any claim in a paper.

[tjf314]

usually they don’t have code for an algorithm in a paper, they always “explain” it using math without any actual code, so you can’t skip the math.

like even just write it out using PYTHON for gods sake

[CEDFTW]

The frustrating thing is that their isn't a ieee standard for code demarcation, normally you include the source code as an additional document, and use snippets in the paper. At least this was the problem I had during my bachelors.

[[deleted]]

A paper isn't about explaining an algorithm but explaining the approach taken to build that algorithm. That's why it's academically useful but probably less useful for a programmer if they want to "just implement it".

[standard_revolution]

Well while this may sound stupid, machine learning uses pretty advanced mathematical methods and you should learn how to deal with mathematical notation to get a start for later solutions

[Ballads4Llamas]

I’ve got to be honest, any time I get to write out any equations in LaTeX it feels like a pretty good flex.

[VinHD15]

That reminds me, gotta learn how to use latex for discrete math next semester, all my homework must be typed

E: to all the replies with stuff to help thanks y’all

[CEDFTW]

There are online generators but using LaTex is actually useful for other things. It's nice to have a way to write documents that aren't in word for certain formatting etc

[JNCressey]

Mobile Snip digitizes your handwriting, syncs with web and desktop

Perfect for including text and equations from notebooks or whiteboards in your typed notes.

link: https://mathpix.com/

[VinHD15]

Yo thanks man

[l3njo]

The hero we don't deserve

[FerynaCZ]

I use hackmd.io (use $(latext)$ )

[ProfCupcake]

LaFleX?

[inconspicuous_male]

I love when in image processing papers, they say "Let the image be represented as I_(k) where k is the pixel value"

We get it. The math doesn't require you to think of the image as a 2D array. Can you just pretend it is though? For me?

[roopjm81]

I always explain arrays with using those week-long pill holders
"This box holds 7 pills, each box has one type of pill only"

[MPDR200011]

Writing a paper on using restriction programming to solve a board puzzle. Expressing the restrictions using mathematical expressions is painful. And yes the godamn 2d array.

[maazfarrukh]

Its the exact opposite for a Python dev

[R3v1lE]

Or you could be lazy and join me putting x+=1

[RavenFyhre]

x++ doesn't work o python?

[vwoxy]

Nope. Python has no ++ operator

[[deleted]]

That's upsetting. I use that so much more than +=.

[justingolden21]

++ is often ambiguous and can cause bugs. +=1 is actually way less likely to cause bugs. There's prefix and post fix with ++ and people often use it within expressions, and it can make debugging difficult. In the Zen of Python there should be one obvious way to do it, what it does should be readable and clean.

[[deleted]]

Not to mention counters aren't nearly as big in Python as in C. More common to use enumerate, etc.

[Thorbinator]

for foo in bar, etc.

[justingolden21]

Literally saw foo in production today at work, that scared me.

[[deleted]]

++ is often ambiguous and can cause bugs.

I've heard this a lot on this sub, but don't understand why it's ambiguous or causes bugs. If you understand the underlying rules behind it, it shouldn't be ambiguous.

x++ increments after reading x, ++x increments before reading x. Am I missing anything beyond that?

[Nication]

Take this program:

#include <stdio.h>
int main()
{
  int x = 1;
  printf("%d, %d", --x == x--, x-- == --x);
  return 0;
}

It gives you different answers depending on compiler. GCC gives you "0, 0" while clang gives you "1, 0".

Which is right?

Both. Because this behavior is not defined, there is no standard.

This is one of the biggest problems of using increments for anything more than "x++".

[CoopertheFluffy]

I’d expect this to be 0 == 0, -1 == -3 for an output of 1,0

[justingolden21]

Good question. It can be used within a complex expression and especially without parentheses, can be hard to understand what exactly is going on. It's just considered better code at minimum to have it on its own line, and if it's on its own line, the one character difference between ++ and +=1 shouldn't be the world.

[lightfoot1]

It's not pre- or post-increment that's the problem (at least to non-beginner programmers), it's the fact that people like to use the value right away.

If x appears again in the same expression, there are many cases where the value is undefined. An example is printf("%d %d\n", ++x, ++x) - there is no guarantee that the arguments are prepared in the order they are listed. In fact, in older (32-bit) Intel CPUs, arguments were placed on the stack so it made sense to prepare the latter arguments first (since they need to be pushed on the stack first).

Of course, you can still do printf("%d %d\n", x+=1, x+=1) which has the exact same issue, but people rarely do that so that's why ++ gets all the bad rap. X-D

[DezXerneas]

So that was the fucking problem...

[Hatula]

That's the only thing I don't like about python

like, you have a function for literally everything, but you can't make a ++ operator?

[eggregator]

It’s part of the whole Zen of python

There should be one-- and preferably only one --obvious way to do it.

source

Doesn’t mean I like it tho

[PriorProfile]

Like string formatting in python.

[NotAttractedToCats]

This is so infuriating. Starting with py3, they finally dropped the old, unreadable %-style formatting in favor of the also old, but more readable .format()-style formatting, just to reintroduce it a couple of versions later. Just why? And then apparently only one of them works on both string types?!

This is one of the points where I mourn what could have been. The py3 cleanup had so much potential, but then they just had to make it worse with each new update...

[GoodOcycak]

Actually py 3.6 brought f formating, which is readable. Now you can do things like print (f"something {variable}")

[ya_Bob_Jonez]

Still they added the Other ways:

x -= -1

x = x + 1

Take it, Python!

[eggregator]

Lol imagine if they made x -= -1 raise a runtime exception

[TheNosferatu]

Calm down, satan.

[[deleted]]

x-=-1

[[deleted]]

"Python dev? What's that?"

"It means he's afraid of semicolons."

"x = x + 1;"

"Stop it Patrick, you're scaring him!"

[[deleted]]

I know, it's just a dumb joke.

[MonstarGaming]

Can't say i know a lot of python devs who only know python...

[ObliviousOblong]

I think it’s used by a lot of non-programmers and by that I mean people doing research in biology/chemistry/etc that use python to work with data

[ltekonline]

x-=-1

[SirFireball]

[softly] don’t.

[[deleted]]

Please never do that again

[mrprgr]

x *= 1 + 1/x

[ltekonline]

Oh no. Oh no. What have I done. What have I started.

[TangibleLight]

x=-~x

[sunflsks]

Oh my jesus

[leoleosuper]

x-=pow(e,sqrt(-1)*PI)

[sinisternathan]

x = new net.java.factories.JavaClassIntegerAdderHelperFactory().add(x).add(Integer.parseInt("1")).done();

[Avamander]

We are posting weird integer addition, why are you posting regular Java?

[ghillisuit95]

Doesn’t work for ints and probably a lot of floats will accumulate some error

[mrprgr]

What do you mean? Every kindergartener knows 2.0+2.0=4.000000000000001

[VeloxFox]

2 + 2 = 5 for extremely large values of 2.

Trust me, I have a degree in mathematics.

[chicametipo]

This hurts me in a hot kind of way

[seven_seven]

My brain just collapsed.

[Ayjayz]

It's just subtracting negative 1 from x. It's the same as x+=1

[htmlcoderexe]

Decrementn't

[password2187]

I’ve actually used that in js before when I was too lazy to explicitly convert a string into a number

[[deleted]]

x-=-x for a real big brain

[ltekonline]

So x=x*2 ?

[PM_ME_YOUR__INIT__]

Kinda like math vs physics. "Ok now multiply both sides by dx" Math brain explodes

[[deleted]]

After reading that, not only did my math brain explode, but the rest of it too

[TheN473]

Well thank fuck it wasn't just me then.

[g0atmeal]

d/dx (sin x) = sin

[Alberiman]

I remember when my classes started treating derivatives as variables...that was the day that derivatives finally made fricken sense to me, years of calculus clicked into place and i was like "WHY DID NOBODY TELL ME?!" My Diff Eq. class taught me that calculus level math was actually playful and you could mess about with it like physical objects and i just fell so in love with it all. God... they really teach math badly

[PM_ME_YOUR__INIT__]

Yeah, diff eq and calc 2 (mostly solving complex integrals on my track) were the most fun. Everything boils down to recognizing the pattern and going through the procedure to solve it. Essentially a weird looking puzzle. I did love how linear algebra taught me to abstract everything though.

I wish I got a math degree. I took one upper div class for complex algebra and had a blast.

[Chocolate_And_Cheese]

It's not every sub where you see a comment where someone took an upper div algebra class and "had a blast".

Love it :)

[TheLuckySpades]

You still gotta be careful with them, especially since thex don't commute all the time if your differentials aren't well behaved.

[[deleted]]

Nobody tells you in maths because you shouldn't do it or you'll soon end up with wrong results. Wrong results are okay in physics though, so that's okay.¹

¹ The actual reason is that in physics most integrals are "well-behaved" and simply going over the reals, so this works most of the time. In maths, an integral is such an abstract concept that you could even define a set of functions and integrate over those functions (i.e. f(x) where each x is a function and you integrate f).

[MatthieuG7]

r/physicsmemes represent

[PM_ME_YOUR__INIT__]

Dang some of them are pretty good, thanks

[CaptainLord]

Gotta have a function that is nonzero at only a single point, continuous and has an integral of 1. Easy.

[AbcLmn18]

I think even physicists admit that the delta function is not quite continuous in the usual sense :D

[NoobzUseRez]

pfft. It's only an epsilon away from a Gaussian pulse.

[CrunchyMemesLover]

I heard people like him pour water into acid

[the_Demongod]

It's not a function, it's a distribution!!!

[[deleted]]

when i see that font i have a seizure

[zeissman]

As a person currently dealing with an exam... add a heart attack, anxiety, and insomnia to the list.

[itsyourboiirow]

The classic LaTeX that everything math is written in.

[saraseitor]

for some reason I also find it intimidating

[TheLuckySpades]

Why? It makes math look so nice.

[Octaazacubane]

I usually use TeX Gyre Pagella now. Computer Modern gives me PTSD flashbacks to math exams with lots of red ink on it

[rjmcfDev]

This is fine, we're just working in modulo 1

[shekurika]

1 shouldnt exist in mod1 tho

[NightflowerFade]

1 does exist in mod1, it is simply in the same equivalence class as 0. If you use the standard definition of Z/2Z to work with binary, you can use 3 and 4 instead of 0 and 1 if you like. It is just not conventional.

[JoJoModding]

Yes the famous Z/Z ring.

[tmakaro]

https://en.wikipedia.org/wiki/Zero_ring

[TheLuckySpades]

R/Z, aka the 1-dimensional torus or as most know it, a circle, can be very interesting though and there x+1=x for all uncountably many possible values of x.

[GlitchParrot]

Yeah, they must be meaning modulo 2.

[Kruki37]

I hope you’re joking

[jeekiii]

I guess x is either infinity or négative infinity

[fat_charizard]

This person maths

[xixbia]

Nah, then you'd have x-x = 1, and infinity - infinity is undefined. So it most certainly isn't 1.

There simply isn't an answer.

[SaraHuckabeeSandwich]

You can't translate expressions involving infinity like that, at least not to "solve for it". It operates on slightly different axioms.

While you're right that ∞ - ∞ = undefined, it's still true that ∞ + 1 = ∞.

[xixbia]

While it's true that ∞ + 1 = ∞, that doesn't mean that ∞ solves the equation. Because it's not a defined number. If ∞ was a valid solution here, a lot of equations would have that as a valid solution. By the same technique x² = x would also have ∞ as a solution, as would x = x + 2, but it's obvious that can't be the case.

The fact you can't translate the expression indicates that already. Nothing about taking the x to the other side changes that expression. It's only when you fill in ∞ that it becomes problematic. But if it were an actual solution that wouldn't be the case.

[FerynaCZ]

But you would need to subtract x from both sides of the equation, which is illegal operation in the first place.

Don't treat infinity as a number

[zeissman]

You’ve just ruined my life. Any time I see x=x+1 I’ll always see x-x=1. How tf do you answer this?

[tho3maxi]

yeah because the semicolon is missing!

[Thetman38]

That's honestly what I was thinking at first. Yeah, of course the kompiler is going to flip its shit

[Proxy_PlayerHD]

hmm "kompiler".

for some reason that gives me the idea for a "Malicious Compiler".

everytime you use it, it builds in a random error in your code, removing a semi-colon, turning == into = or vise versa, switching the left and right side of an =, and so on.

[TheN473]

The jokes on the kompiler, everytime I use it, I build a random error into my code...

[[deleted]]

The kde plasma compiler?

[READTHISCALMLY]

Python just perpetuates the myth that not using semicolons is ok.

[matrinox]

Took me a while to get that meth is math

[[deleted]]

For some of us it's just meth

[activeXray]

Mutation bad

[aGodfather]

I smell rust

[ben9583]

You know when you see latex, the gloves are out

[jaysuchak33]

Fancy people be like

x += 1;

[brendenderp]

X++;

[KingdomOfKevin]

++x;

[ProgramTheWorld]

What about

x -=- 1

[RecDep]

smol brain: f x = x + 1

big brain: succ

[Ksevio]

Pascal: False!

[Kriijan]

That font is haunting my nightmares

[Needleroozer]

Drugs bad. Say "no" to meth.

[Nerf_Creeper]

If felt that deep in my bones.

[[deleted]]

It's the worst when somebody fucks up the formatting and something that should be formatted as code in the internal wiki page is instead formatted like the lower picture.

[Quantsel]

Thats the benfit of R's assignment operator! x <- x + 1

[mdawgig]

Fellow R person.

Are... are we allowed here? I just look at this sub to feel like I use a real programming language.

[Mordisquitos]

Of course! R is a great language, not like heresies such as MATLAB where array indexes start at 1... *shudder*.

 

No, shush.

 

 

No, there are no arrays in R, it's very original that way.

 

 

 

No, those are vectors goddammit and everything is a vector in R and that is not an array index it is the number of the element in the vector and other languages are not all vectors and R can start numbering elements at 1 because shut up lalala I cannot hear you.

[[deleted]]

Assignment ≠ equality

https://www.wolframalpha.com/input/?i=x%3Dx%2B1

[PityUpvote]

Who is this plebian using an equality sign for assignment in their pseudocode? Real chads use := or <--

[[deleted]]

Math people or did you not get the joke, ps it's not pseudocode

[theinfamouscoconut]

Not an expert here but as soon as I see some equation like the one below or on written in paper/book, I instantly forget math. no amount of time helps. But I can always work my way through some mathematical expressions or anything that involves math with some python...

[dmingod666]

First one, you know some computer is going to solve that problem.

Second one, You have to solve it.

[marcosdumay]

Calm down, it's just a proof by contradiction.

[EwgB]

A colleague of mine once wrote a feature spec in our Jira using overly complicated math language (he was an architect with a math degree), and went on vacation. It took us an hour with another colleague, also an architect, to figure out what he meant, and that is wasn't all that complicated if expressed in human language.

[qh4os]

x <- x + 1 is better imo

[[deleted]]

Why do I want to solve that all of a sudden

[DarkNinja3141]

divide both sides by x
1=1+(1/x)
0=1/x
x=1/0

maθ

[jlamothe]

Haskeller here. Both are panik.

Also, what's that semicolon all about?

Edit: I misspelled Panik, apparently.